Indigo coloring-matter containing halogen and process of making same.



' UNITED STATES Patented June 2, 1903.

PATENT OFFICE.

PAUL ERWIN OBERREIT, OF LUDWIGSHAFEN-ON-THE-RHINE, GERMANY, ASSIGNOR TO BADISCHE ANILIN AND SODA FABRIK, OF LUDWIGS- HAFEN-ON-THE-RHINE, GERMANY, A CORPORATION OF- BADEN, GER- MANY.

lNDlGO COLORING-MATTER CONTAINING HALOGEN AND PROCESS OF MAKING SAME.

SPECIFICATION forming part of Letters Patent N 0. 730,148, dated June 2, 1903. Application filed February 11,1902. Serial No. 93,538. (Specimensd To all whom, it may concern:

Be it known that I, PAUL ERWIN OBER- REIT, doctor of philosophy and chemist, a sub- .ject of the King of Saxony, residing at Ludwigshafen-on-the-Rhine, in the Kingdom of Bavaria, Germany, have invented new and useful Improvements in Indigo Coloring- Matters Containing Halogen, of which the following is a specification.

This invention relates to new indigo coloring-matters containing bromin, and process of producing the same. These products will hereinafter be referred to by the generic term brominated indigo. 1

The process employed in this invention. consists, essentially, in converting brominated phenyl-glycocoll-ortho-carboxylic acid into, for instance, acetylated brom indoxyl derivatives and finally converting these products into the corresponding brominated indigo coloring-matters. This can be carried into practical effect by treating a brom phenylglycocoll-ortho-carboxylic acid (preferably in the form of its sodium salt) with, say, acetic anhydrid, acting on this result (preferably in the dry and purified state) with, say, causticsoda solution, and then blowing air through the so obtained liquid. The brominated phenylglycocoll -orthocarboxylic acid em-. ployed can be obtained by direct bromination of phenylglycocoll ortho carboxylic acid itself orby brominating the nitrile of that acidnamely, cyan-methyl-anthranilic acid, which is described in United States Letters Patent No. 662,754, dated November 27, 1900-and subsequently converting the soobtained product into brominated phenylglycocoll-ortho-carboxylic acid by suitable saponification.

In the following; examples the nature of this invention is further illustrated, but this invention is not limited to the proportions and conditions therein given. The parts are by weight and the temperature degrees refer to the centigrade scale.

I. Production of Brominated Phenyl- Glycocoll- Ortho- Ocarbozrylic Acid.

A. From phenyl-glycocoll-ortho-ccwbowylic acid. -Suspend one hundred and ninety-five hours.

(195) parts of phenyl glycocollortho carboxylic acid in six hundred (600) parts of glacialacetic acid. Add gradually and stirring the meanwhile one hundred and sixty (160) parts of bromin'. Let stand for several Pour the result into three thousand (3,000) parts of water. Filter and washwith water until the filtrate no longer contains halhydric acid, as shown by testing with silver nitrate. The mono-brom-phenyl-glyco coll-ortho-carboxylic acid so obtained, when purified by recrystallization from ethyl alco- 1101, can be obtained in the form of yellow needles, melting at about two hundred and twenty-eight (228) degrees.

In place of the glacial acetic acid of this example benzene or ligroin may be employed.

B. From 0ycm-methyl-anthrcmdic CtCtd. Suspend one hundred and seventy-six (176) parts of cyan-methyl anthranilic acidin six hundred (600) parts of glacial acetic acid and add one hundred and sixty (160) parts of bromin, cooling the meanwhile. At first solution ensues and then the mono-brom-cyan-methylanthranilic acid beginsto separate out. When no further separation takes place, filter off the solid material and wash with water. The acid when purified by crystallization from ethyl alcohol occurs in yellow needles, melting at about two hundred and nine (209) degrees. (See Journalfi'm" Praktische Ghemz'e, N. F. Vol. 63, page 403.) To convert the so-obtained brom cyan-methyl-anthranilic acid into the corresponding brom-phenyl-glycocoll-orthocarboxylic acid, boil it with an excess of canstic-alkali solutionsay caustic-soda solution containing about fifteen (15) per cent. of caustic soda, (NaOH)until' ammonia is no longer given oif, then cool and precipitate the sodium-carbonate solution and subsequently 5 evaporation to dryness water bath.

II. Production of Brom'i'nated Indigo. Boil one (1) part of the dry and finely-powon, say, a boilingdered sodium salt of inono-brom-phenyl-glycocoll-ortho-carboxylic acid with from three (3) to four (4) parts of acetic anhydrid until evolution of gas ceases, then distil oif the excess of acetic anhydrid in 'vacuo. The dry residue may be directly operated upon, but it is preferable to extract the same with water and to recrystallize this residue from alcohol and finally from ligroin. Now saponify this product (which is to be regarded as diacetylbrom-indoxyl) by means of an excess of canstic-soda solution, blow air through the resulting liquid, and collect the dibrom-indigo so resulting in any suitable manner. This product resembles ordinary indigo in its external appearance, but is distinguished from ordinary indigo by its containing broinin and by producing a clearer and more reddish shade when dyed on cotton from a Vat such as is adapted for dyeing with ordinary indigo. This coloring-matter does not impart a blue color to cold glacial acetic acid, cold carbon bisulfid, cold chloroform, or hot ethyl alcohol.

\Vhat is claimed is 1. Process forthe production of brominated indigo which consists in acting upon cyanmethylanthranilic acid successively with brom, caustic alkali, acetic anhydrid, caustic alkali and air.

Process for the production of brominated indigo which consists in acting upon brominated cyan-methyl-anthranilic acid successively with caustic alkali, aceticanhydrid, caustic alkali and air.

3. Process for the production of broinin ated indigo which consists in acting upon brominated phenyl-glycocoll-ortho-carboXylic acid successively with acetic anhydrid, caustic alkali and air.

4. Process for the production of brominated indigo which consists in acting upon acetylated brominated indoXyl with caustic alkali and air.

5. Processfor the production of dibrolnv PAUL ERW IN OBERREIT.

\Vi tnesses:

ERNEST F. EHRHARDT, JACOB ADRIAN. 

